Viridans Streptococci
Mostrando 25-36 de 236 artigos, teses e dissertações.
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25. Association of cell-adherent glycocalyx and endocarditis production by viridans group streptococci.
To assess the role of glycocalyx production in the pathogenesis of endocarditis caused by viridans group streptococci in adult patients, glycocalyx production was examined for 49 blood culture isolates. The tryptophan assay, a quantitative spectrophotometric test, was used to measure cell-adherent glycocalyx production. Absorbance values of the isolates that
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26. Role of immunoglobulin G in platelet aggregation by viridans group streptococci.
The aggregation of human platelets by the viridans group streptococci requires both direct platelet-bacterium binding and plasma components. Some of these extracellular constituents (e.g., fibrinogen) are cofactors for ADP, which mediates the terminal events in platelet activation by these organisms. In addition, other plasma components which are specific fo
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27. Screening for penicillin tolerance in viridans streptococci by a simple disk method.
A disk method was developed for demonstrating penicillin tolerance in viridans streptococci. This was achieved by the substitution of the penicillin disk used for susceptibility testing by a disk containing penicillinase. After reincubation, penicillin-tolerant strains exhibited new growth in the area adjacent to this disk, providing a rapid screening test.
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28. Bile-Esculin Test for Presumptive Identification of Enterococci and Streptococci: Effects of Bile Concentration, Inoculation Technique, and Incubation Time
The bile-esculin test is used to differentiate enterococci and group D streptococci from non-group D viridans group streptococci. The effects on test performance of the concentration of bile salts, inoculum, and duration of incubation were examined with 110 strains of enterococci, 30 strains of Streptococcus bovis, and 110 strains of non-group D viridans gro
American Society for Microbiology.
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29. Identification of viridans streptococci isolated from clinical specimens.
Of 532 strains of viridans streptococci isolated from clinical specimens, 517 were identified by using a scheme based on the work of Facklam (R. R. Facklam, J. Clin. Microbiol. 5:184-201, 1977). The strains were distributed among nine of the species described by Facklam and an additional group of physiologically homogeneous streptococci not recognized in Fac
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30. Distribution of Subclasses mefA and mefE of the mefA Gene among Clinical Isolates of Macrolide-Resistant (M-Phenotype) Streptococcus pneumoniae, Viridans Group Streptococci, and Streptococcus pyogenes
The distribution of subclasses mefA and mefE of the mefA gene among 116 M-phenotype streptococci was as follows: pneumococci (38 strains had mefE and 4 mefA), viridans streptococci (49 mefE and 1 mefA), and Streptococcus pyogenes (24 mefA). Spain9V-3-14 and England14-9 clones of serotype 14 were dominant among pneumococci.
American Society for Microbiology.
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31. Multiply resistant viridans streptococci: susceptibility to beta-lactam antibiotics and comparison of penicillin-binding protein patterns.
A unique group of viridans streptococci has been found in South Africa. These organisms were isolated in close temporal and physical proximity to the isolation of penicillin-resistant pneumococci. The strains were resistant to penicillin, oxacillin, the cephalosporins (all generations), piperacillin, azlocillin, and mezlocillin but were susceptible to vancom
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32. Comparative evaluation of the API 20S and AutoMicrobic gram-positive identification systems for non-beta-hemolytic streptococci and aerococci.
The API 20S system (Analytab Products, Plainview, N.Y.) and the AutoMicrobic Gram-Positive Identification system (GPI; Vitek Systems, Hazelwood, Mo.) were evaluated for their capacity to identify the non-beta-hemolytic streptococci and aerococci to the species level. The 20S system identified 86% (six of seven strains) of nonhemolytic group B streptococci, w
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33. Clinical significance of viridans streptococci isolated from blood cultures.
The clinical significance of viridans streptococci isolated from the blood cultures of 86 patients was determined. Isolates that were significant or suggestive of infection represented only 21% of the cases. Among 54 isolates for which the species was known, Streptococcus sanguis II was the most common. However, a significant association between species and
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34. Binding of viridans group streptococci to human platelets: a quantitative analysis.
The binding of viridans group streptococci with human platelets was analyzed by two-color flow cytometry. Binding was detected within 15 s of mixing bacteria and platelets. At ratios of bacteria to platelets of 1:1, 10:1, 100:1, and 1,000:1, the percentages of bound streptococci (mean +/- standard deviation) were 93.2% +/- 5.4%, 80.0% +/- 8.6%, 39.8% +/- 11.
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35. In Vitro Activities of the New Ketolide HMR 3647 (Telithromycin) in Comparison with Those of Eight Other Antibiotics against Viridans Group Streptococci Isolated from Blood of Neutropenic Patients with Cancer
The in vitro activities of the ketolide telithromycin and eight other antibiotics were tested against 77 strains of viridans group streptococci isolated from blood samples of neutropenic patients. Thirty-one (40.3%) of the strains were resistant to penicillin G, and 27 (35.1%) were resistant to erythromycin A. Telithromycin (MIC range of ≤0.03 to 1 μg/ml)
American Society for Microbiology.
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36. In Vitro Activity of Telithromycin against Viridans Group Streptococci and Streptococcus bovis Isolated from Blood: Antimicrobial Susceptibility Patterns in Different Groups of Species
The in vitro activities of penicillin, erythromycin, clindamycin, and telithromycin were determined against 155 viridans group streptococci (VGS) and 18 Streptococcus bovis blood isolates. Heterogeneity in the susceptibility patterns and macrolide resistance phenotypes and genotypes in the different groups of VGS was detected. We found seven telithromycin-re
American Society for Microbiology.